A door that won’t close properly can be very annoying. Usually the solution is adjusting the alignment of the strike plate in relation to the door latch.
Start by tapping the metal tab in the strike plate with a screwdriver and hammer to bend the tab slightly. If that doesn’t fix it, loosen the screws on the strike plate and tap the entire plate toward the door opening.
Watch this video to find out more.
When a door won’t stay closed, the problem is usually with the strike plate and not the door itself. Begin by tapping the small metal tab inside the plate toward the door with a hammer and screwdriver. This will open up the hole in the plate so the bolt can drop in more easily.
If this doesn’t do the trick you may need to loosen the screws holding the plate and tap the whole unit toward the door or possibly remove it altogether and remount it closer to the edge of the casing.